diff --git a/reference/classobj/functions/get-class.xml b/reference/classobj/functions/get-class.xml
index 20472dd41d..7a2d4fb069 100644
--- a/reference/classobj/functions/get-class.xml
+++ b/reference/classobj/functions/get-class.xml
@@ -9,7 +9,7 @@
   &reftitle.description;
   <methodsynopsis>
    <type>string</type><methodname>get_class</methodname>
-   <methodparam choice="opt"><type>object</type><parameter>object</parameter></methodparam>
+   <methodparam choice="opt"><type>object</type><parameter>object</parameter><initializer>&null;</initializer></methodparam>
   </methodsynopsis>
   <para>
    Gets the name of the class of the given <parameter>object</parameter>.
@@ -57,6 +57,14 @@
       </row>
      </thead>
      <tbody>
+      <row>
+       <entry>Since 5.3.0</entry>
+       <entry>
+        &null; became the default value for <parameter>object</parameter>,
+        so passing &null; to <parameter>object</parameter> now has the same
+        result as not passing any value.
+       </entry>
+      </row>
       <row>
        <entry>Since 5.0.0</entry>
        <entry>